Effect of Physicochemical Properties on Nanoparticle Fate and Transport in Unsaturated Porous Media

The overarching objective of this proposal is to elucidate the key factors governing the fate and transport of nanoparticles (NPs) in unsaturated porous media. Model NPs with a range of physicochemical properties (e.g., surface charge, size, shape, density, etc.) will be synthesized and be used in the proposed project. It is hypothesized that the NP properties as well as the surrounding environmental conditions are the dominant factors that govern their mobility in unsaturated porous media. To test the hypothesis and accomplish the overarching objective, the following specific aims will be pursued: 1) synthesizing and characterizing stable dispersions of model nanoparticles with different size, shape and surface functionalization; 2) relating physicochemical characteristics of the model NPs to their adsorption in unsaturated porous media; and 3) relating physicochemical characteristics of the model nanoparticles to their transport in unsaturated porous media. Laboratory experiments and modeling tools will be used to elucidate the governing mechanisms. Because NPs are forecasted to enter different environmental compartments, especially in soil and groundwater systems, the successful completion of this project will help improve current theories and models of their fate and transport, resulting in more accurate predictions of conditions under which soil and groundwater contamination may take place. Consequently, this will contribute greatly to the fundamental knowledge needed to prevent soil and groundwater pollution and protect environmental health in general.

This research project will be integrated with education by training graduate, undergraduate, and pre-college students with a diverse array of backgrounds. Students who are members of underrepresented groups will be included as major participants in the proposed research activities. In addition, this proposed research will be coupled with the existing NSF-REU (Research Experience for Undergraduates) programs at the university. This research will bring highly skilled, nationally competitive students to the university and the students and faculty will have an opportunity to be exposed to the state-of-the-art technology adopted in this research. Results of the proposed research will be disseminated widely. Beyond publications and conference presentations, the investigators will work closely to enhance public awareness of the importance of this research. Findings from this project will be disseminated widely to regulators, industries, and other practitioners through workshops, monthly newsletters, flyers, and public domain websites. It will help improve models to make possible more accurate predictions of the conditions for soil and groundwater contamination by NPs.